In traditional Chinese medicine (TCM), a Chinese medicine practitioner (CMP) performs pulse palpation by manually sensing, at three levels: a superficial level, a middle level and a deep level, a person's pulse at a number of different locations on the radial artery around the wrist of the person. By sensing and analyzing the signal of the pulse, the CMP performs medical diagnosis on the person, i.e. the patient, according to medical principles of the TCM.
In recent years, it is possible to perform pulse sensing by a device. Machine-based sensing of a person's pulse provides certain advantages over pulse sensing by CMPs. These advantages include efficiency and repeatability. In addition, a signal processor can be used to process the signal sensed by the pulse-sensing device, thereby enabling implementation of an automatic medical-diagnosis system.
In a pulse-sensing device, an actuator is usually used to move and position a pulse-sensing sensor onto a person's wrist. Typically, as in disclosures of CN101049247, TW20113233 and TW200727865, the actuator is of a linear-translation type so that an actuating force is directly applied to the sensor for making a linear movement. When the sensor is pressed onto the wrist, a certain level of the actuating force is still maintained in order to secure the sensor onto the wrist for pulse sensing. In general, the actuator generates the actuating force that is subject to random noisy fluctuation. This noisy fluctuation is directly superimposed onto the sensor, which is usually a pressure sensor for pulse sensing, so that the sensed signal of the person's pulse is significantly corrupted by the noisy fluctuation of the actuating force. Although one can considerably reduce this noisy fluctuation by using a hydraulic actuator (which can be configured to achieve a high degree of stability in the generated actuating force), the hydraulic actuator is bulky, difficult for maintenance, and expensive. Advantageously, it is desirable to have a light-weight, low-cost pulse-sensing device.
There is a need in the art for a pulse-sensing device that a sensed signal of the pulse is not significantly impacted by a noisy disturbance of an actuating force without a need to employ a highly-stable actuator.